Jun 21, 2017

The generous sex life of the cabbage white butterfly

David Cook / Flickr Creative Commons

Scientist Nathan Morehouse has discovered that one of the most common butterflies — the white cabbage — has an unusual sex life, including large, protein-rich ejaculates that nourish the females as they produce offspring, according to the Atlantic.

How it works: Male butterflies ejaculate a solid package (unlike humans) of sperm called a spermatophore, which is often 13% of its body weight. The package is left in a pouch in the female's reproductive tract where the sperm moves on to a second pouch where it will later fertilize eggs. The rest of the protein-packed spermatophore is broken down for the female's nourishment. One spermatophore provides females with the nutrients needed for almost half of the eggs they'll lay.

While the white cabbage butterflies look common and plain to humans, their wings reflect the sun's UV rays, which give the females a lavender color and males a glowing purple color. The brighter the purple of a male, the more attractive it is to a female as it is a reflection of the butterfly's fitness and the nourishment the female might receive.

Clock's ticking: Scientists think male butterflies have sex 2-3 times in their life. Females, who have leftover spermatophore shells that can be counted, typically mate 2-3 times, but as many as 6 times in a lifespan.

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